Dancing With the Stars pro Mark Ballas has reportedly suffered an injury while rehearsing and may not be able to dance Monday night.

Ballas, who is paired with UFC fighter Paige VanZant this season on Dancing With the Stars, apparently injured his back on Sunday, according to a new People report.

"He injured his back at camera blocking rehearsal on Sunday," a source told the publication in a new report posted Monday afternoon. "It's an old injury that he aggravated. It's up in the air if he'll be able to perform tonight."

Just in case Ballas is not cleared to perform, VanZant has been rehearsing with Alan Bersten now, says the publication. Bersten has been a dance troupe member with the show since season 20 and is a former So You Think You Can Dance contestant.

This isn't the first time a pro has been injured during Dancing With the Stars. Derek Hough was injured during season 20, with Sasha Farber filling in for three weeks as Nastia Liukin's partner. Last season, Peta Mugatroyd suffered ligament tearing before the premiere and had to sit out the entire season. She was supposed to be partnered with Andy Grammer.

VanZant and Ballas received a score of 21 out of 30 for their first dance in last week's premiere. They performed a foxtrot to "Ain't Got Far to Go" by Jess Glynne, which you can watch below.

So far there's been no announcement by either VanZant or Ballas that anything different is happening tonight. However, VanZant did note in an Instagram post today that things will be "wild."

 Today is a wild one. Keep up on snapchat as things happen. We're going to need some extra votes today. Calling my #fanzants again tonight.

A photo posted by Paige VanZant (@paigevanzantufc) on Mar 28, 2016 at 9:45am PDT


"Today is a wild one. Keep up on snapchat as things happen. We're going to need some extra votes today. Calling my #fanzants again tonight," she wrote

Dancing With the Stars airs Mondays at 8 p.m. ET/PT on ABC.